Ceiling heating system



June 10,1941.

lG.FUcHs CEILING HEATING SYSTEM Filed May 2, 1938 2 Sheets-Sheet 1 June 10, 1941.

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Patented June 1G, 1941 UNITEDI STATES PATENT oFFlcE CEILING HEATING SYSTEM Gnter Fuchs, Schwarlenbaoh-on-the-Saale, Germany Appucaunn my z, 193s. seria No. 205,541; In Gumy my s, 1937 5 Claims. (Cl. 237-46) My invention relates to ceiling-heating systems.

In such systems, as constructed heretofore, heating elements which may be water or steam pipes, or electric heaters, are embedded in the ceiling. Thisinvolves the drawback that the ceiling must be of special construction and its initial cost is high in proportion. Other drawbacks are that the system responds but slowly to regulation of the heat, and that, if its elements are water or steam pipes, the system will give trouble upon any, even slight, deflection of the ceiling.

It is an object of my invention to provide a ceiling-heating system in which the aforesaid drawbacks are eliminated.

To this end, I dispense with the heating elements in the ceiling altogether and instead provide means for discharging heated air into a room below its ceiling, so as to produce a layer of heated air below the ceiling.

Since the ceiling contains no heating elements, it can be constructed as usually and at normal initial cost. The few pipes, or nozzles, required for conducting and discharging the heated air, are arranged without difficulty, and without interfering with the ceiling structure. 'Ihe lower surface ofthe ceiling below which the layer of heated air is formed, has the double function of a heating and of a radiating surface, there is no .temperature gradient between the surface and the layer, and the temperature of the layer can be comparatively low. On the other hand, the emciency of my system is high and it is operated at. low cost.

In the accompanying drawings a system embodying my invention is illustrated by way of example.

In the drawings Fig. 1 is a vertical cross-section of a ceiling equipped with a single air-discharge nozzle of circular cross-section within the ceiling, and a pair of suction nozzles arranged below the ceiling, for withdrawing the heated air after it has partly cooled.

Fig. 2, at the left of its central line, is an axial section, and, at the right of its central line, is an elevation, of a'unit comprising a discharge n ozzle for heated air, and a suction nozzle for the partly cooled air, which suction nozzle is arranged co-axially within the discharge nozzle, with its opening below that of the discharge Fig. 3 .is a vertical axial sectionof an air heater arranged below acelling.

' are defined between the sides of the beams,

planks supporting nlling material below the floor boards 2l, and ceiling planks 2 secured to the lower sides of the beams. 3 is a layer of insulating materialbelow the planks 2, and l is a thin layer of plaster below the insulating layer 3.

A horizontal pipe 25 is arranged within the ceiling l between the oor boards 2| and the planking 2, and supplied with heated air by means which will be described. Thelower end of the pipe 25 is deiiected vertically to form a nozzle 5 whose flaring aperture 9 is just below the plaster layer 4. A circular baille 26 is preferably arranged in front of, and in axial alignment' with, the flaring-aperture of the nozzle, so that the air issuing from the nozzle is deflected in all directions and forms a layer 6 of heated air just below the ceiling. Obviously, any desired number of nozzles may be provided,

' if desired.

The following considerations have led to the adoption of ceiling heating:

During recent years, it was found that from the hygienic point of view it is more important that the walls of a room should be heated, and

`as uniformly as possible than that theair in the room is heated. Even at a very low outside temperature, the walls of a room need not be heated to more than about 20 centigrade to give the human body, and especiallythe body of a person who is reclining, a pleasant sensation of warmth. This means that it-is more important to protect the b ody against radiation to the walls of the room than against convection to the air in the room. If the air alone is heated, the temperature equilibrium of the body is disturbed and an unpleasant sensation is produced which is felt very strongly ifv the heated air contains a high percentage of moisture, but is not felt at all if the air is cool. Heating the air, and not the walls, has the further drawback that the vertical distribution ot' temperature lacks uniformity,v and that large quantities of dust are raised if it is attempted to obtain more uniform distribution by circulation.

By ceiling heating, i. e., by placing the heating surface at the highest point of the room, the undesirable convection to the vroom air is eliminated altogether but, as mentioned, the method employed for constructing the ceiling is not satisfactory. Its high intial cost is due to its extensive and complicated system of heating elements, and to the necessity of making such elements with special care, as they are diiiicultly accese-lsible. Obviously, the construction of the ceiling itself is also more expensive as it must possess greater bearing capacity on account of the extra weight of the elements, and must not be responsive to temperature variations.

If the ceiling is heated by hot water or steam, and the pipes are embedded in the'plaster, it is diilicult, and practicable to a limited extent only, to insulate them against loss of heat in upward direction. The same difficulty is` present in concrete ceilings where the pipes are used as additional armouring members. Pipe lines are also very sensitive to the slightest deflections of the ceiling, as also mentioned. The lines are laid horizontally, and deiiection causes the formation of air or water pockets.

The cost of operation is particularly high if electric heaters are used, but oviously the heat losses from the pipes in steam and water heated ceilings also increase the operating cost.

The slow response of heated ceilings to regulation is due to the bulk of the ceiling acting as a heat accumulator.

On the other hand, ceiling heating is a. vast improvement if the aforesaid drawbacks are eliminated. It produces a gentle radiation toward the floor by which the floor and the walls are heated uniformly, and eliminates heat convection from the body. 'Ihe air in the room is not heated by the radiation, and only very slightly by transfer from the warm walls and floor, and this slight heating is partly made up for by the continuous exchange with the outer air through doors, windows, etc. The temperature of the room air is always below that'of the walls and the floor, it has practically the same specic gravity throughout, and so. there is practically no circulation. Ceiling-heated rooms have a comfortable temperature and the air is cool, fresh, and practically free from dust. The floor is warmer than the air at the level where the heads of the persons in the room are. The heat demand is less than for rooms in which the air is heated, since the air which escapes through windows, etc., is cool.

'I'he heated air which flows from the nozzle, or nozzles, 5 and forms the layer 6 just below the ceiling I, may be produced at a central or in a local steam, hot-water, or electric heater. The layer 6 transfers its heat to the entire surface of the ceiling, or to its major part. The ceiling itself is without any heat-transfer means and so can be constructed like any normal ceiling. The nozzle, or nozzles, 3 and the pipes supplying them with heated air, can easily be arranged in the norma1 ceiling structure. The lower surface of the ceiling, here shown as a plaster layer 4, may be very thin, the plaster being applied directly to an insulating layer shaped like a plate, or a mat. Instead of plaster, light building plates acting as heat insulators," or even heatresistant paper on an insulating layer, may be 6 transfers its heat to the ceiling, there is no temperature gradient between the heating surface and the layer, so that the temperature of the air in the layer can be comparatively low. It has been found that the ceiling should -be heated to to 60 dgs. centigrade according to local and tempera-ture conditions, and that the temperature of the air layer 6 should be 10 to 30 degrees higher, i. e., 40 to 90 degrees centigrade.

Preferably, the air which has given up its heat to the heating surface 4 and is then forced away in downward direction to form a layer 1 of partly cooled air below the upper layer 6, is withdrawn and reheated. This may be effected by a suction nozzle, or nozzles, 8, arranged at some distance below the ceiling but at an ample distance above the heads of standing persons. The heated air in the layers 6 and 1 does not mix with the room air under normal conditions,

and if such mixing does occur accidentally through violent agitation, it is only local and temporary, and in fact is nothing but the permanent condition in systems which heat the room air: a moderate increase in temperature. In

my system, even if mixing accidentally occurs,

used. Since the radiating surface 4 is at the l'it does not raise dust from the floor, and does not cause permanent and non-uniform temperature distribution vertically and within reach of the persons in the room.

It will be understood that my improved ceiling-heating system possesses all advantages of known ceiling-heating systems but is superior to them in many respects, Thus, its initial cost is much lower, since it dispenses with the heating elements in the ceiling and only requires a nozzle, or nozzles, or a local heater with a nozzle, or nozzles. Insulation against loss in upward direction by the layer 3 is more simple, more efiicient, and cheaper, than it can be made in the known systems. The highest temperature prevails at the lower side 4 of the ceiling, so that the heat loss in upward direction is less, with a corresponding reduction in operating cost.

VDeflections and other deformations of the ceilln'g do not interfere with my system, and other trouble is not likely to occur, on account of its simplicity. 'Ihe system responds quickly to regulation, and its thermic inertia is less than in any other system, as only the thin layer of plaster 4 is heated.

` Switching means, not shown, may be provided for cutting in and out the air-discharging and/or heating means, as in electric light installations.

Referring now to Fig. 2, -this shows a combination of a discharge nozzle 5, having a flaring opening 9 at the level of the upper layer 6, and a suction nozzle 21 which is arranged coaxially within the discharge nozzle and has its flaring opening I0 at the level of the lower, or partly cooled, layer 1.

Referring now to Fig. 3, this local air heater I2 is arranged at the inner side of a Wall, be'- low the ceiling, or it may be arranged within the ceiling. The casing of the heater is sur' rounded by a heating jacket, and is preferably equipped with inner radiator ribs I5. Heating medium, such as steam, is admitted to the jacket through a pipe I3 and leaves the jacket through a. pipe I4. Connected to the upper end of the heater is a discharge pipe 28 which opens just below the ceiling I and supplies heated air to .the upper layer 6, and connected to the lower end of the heater is a suction pipe I I which opens at the level of the lower layer 1 for returning the partly cooled air from this layer to the heater where 1t is reheated.

Referring now to Figs. 4 and 5, the ceiling illustrated in Fig. 4 is slightly different from that illustrated in Fig. 1, but it is obvious that the adaptation of my invention is vnot limited to any particular type of ceiling. Light building plates 24 are secured to the lower sides of the beams instead of the planks 2 in Fig. 1, and insulating material 23 is placed on the plates. 'I'he lower side of the plates is covered with plaster 4.

Instead of the pipes 25 in combinationl with nozzles 5, as shown in. Fig. 1, I have here provided what will be termed "elongated nozzles, i. e., discharge pipes I6 and suction pipes I8 whose section' resembles the inverted letter U, or V. The elongated nozzles are inserted in the ceiling, with their lower open sides ush with the plas-ter 4, and a plate-shaped baille 20 is placed at some distance below the open sides of the elongated nozzles.

Ihe discharge nozzles are connected to a delivery header I 1, and the suction nozzles are connected to a suction header I9. The crosssection of the discharge and suction decreases toward their free ends, for obvious reasons.

As compared with the arrangement illustrated in Fig. 1, or Fig. 2, or with the heater illustrated in Fig. 3., the arrangement according to Figs. 4 and-5 has the advantage that it avoids stratication of the heated air, i. e., the formation of a hot upper layer 6 and a partly cooled lower layer l, and that, in consequence, there is no appreciable sinking of partly cooled air but the heated air discharged from the elongated nozzles IG is conducted along below the plaster layer 4 by the bailles 20 in horizontal direction, and is drawn into the next adjacent Vsuction nozzles I8 ln the same direction, without any appreciable descent of partly cooled air. A regular flow of heated air is thus produced below the ceiling, and the eciency of this system is equal to the eiciency of individual heaters which, as is known, are more eflicient than collective heating systems. In fact, it embodies the most favorable method of heating by radiation. At the same time, like the system describediwlth reference to Figs. 1 and 2, lt does not interfere with the ceiling structure.

I claim:

1. In a ceiling-heating system, a set. of elon gated discharge nozzles, means for conducting heated air to the discharge nozzles, and aset of elongated suction nozzles, all the nozzles being arranged in, and opening at the lower surface of, `a ceiling for, respectively, discharging heated air into a room below its ceiling, so as to produce a layer of heated air below the ceiling, and for withdrawing. the air from the layer, and a baille arranged in spaced and parallel relation below the aperture of each nozzle.

2. In a. ceiling-heating system, a set of elongated discharge nozzles, and a setd of elongated suction nozzles, all the nozzles being shaped like inverted channels arranged in, and opening at the lower surface of, a ceiling, for, respectively, discharging heated air into a room below the ceiling. so as to produce a layer of heated air below the ceiling, and for withdrawing the air from the layer, and a baille arranged in spaced and parallel relation below the aperture of each nozzle.

3. In a ceiling heating system, a set of elongated discharge nozzles, a pressure header for supplying heated air connected to one end of the discharge nozzles, means for conducting heated air to the pressure-header, a set of elongated suction nozzles, a suction header connected to one end of the suction nozzles, the cross-section of each nozzle being reduced toward its free end, and all the nozzles being arranged in, and opening at the lower surface of, a ceiling, for, respectively, discharging heated air into a room below its ceiling, so as to produce a layer of heated air below the ceiling, and for withdrawing the air from the layer, and a baille arranged in spaced and parallel relation below the aperture of each nozzle.

4. In a ceiling-heating system a set of discharge nozzles, reheating means, means for conducting heated air from the reheatingmeans to the discharge nozzles, a set of suction nozzles, means for withdrawing the air through the suction nozzles, means for conducting the withdrawn air to the reheating means, all the nozzles being arranged in, and opening at the lower surface of, a ceiling, for respectively, discharging heated air into a room below its ceiling, so as to produce a layer of heated air below the ceiling, and for Vwithdrawing the air from tlu.x layer.

5. A ceiling-heating system according to claim 4, characterized by arranging a baille at the discharge nozzle in such a manner that the stream of hot air is deflected practically at right angles to the direction of the discharge nozzle.

GNTER FUCHS. 

